Vehicle manufacturers are continually researching new ways to improve vehicle operator situational awareness on the roadway, for example through improved forward lighting systems, various environmental sensing systems including radar, infrared and vision systems, and vehicle brake light systems. Forward lighting systems may now be found in production vehicles which have a daytime running mode wherein the forward lighting is automatically operated at reduced intensity during certain conditions to improve the vehicle's visibility to other vehicle operators. Similarly, vehicle brake light systems may now be found which include center high mounted stop lamps or CHMSL which are often visible through the windshield and backglass of preceding vehicles which gives other vehicle operators an earlier indication of traffic conditions up ahead than otherwise available by relying solely upon the brake lights of an immediately preceding vehicle. And, the more recent use of light emitting diode (LED) brake lights provides a more instantaneous indication of brake pedal activation than is available with filament-type bulbs. Different schemes are known for indicating brake lights braking events keyed to brake pedal depression, including solid light activation and flashing light activation.
Known vehicle brake light control systems rely on the cooperative arrangement of an electrical brake switch and brake pedal linkage. The brake pedal linkage keeps the brake switch in an open state when the brake pedal remains in a rest or undepressed position. At anytime the brake pedal is depressed, regardless of how far or with how much pressure, the brake switch is closed. The brake switch provides an electrical input to a computer based control which monitors the brake switch state and turns on the vehicle brake lights at anytime the switch is closed and turns off the brake lights at anytime the brake switch is open. Additionally, various forms of vehicle speed and vehicle acceleration data are widely tracked and are known to be used to activate brake light systems.
Known vehicle brake light control systems convey no information to other vehicles on the roadway of the braking vehicle's velocity, nor do they convey varying degrees of information related to the rate of deceleration of the vehicle. Such systems, for instance, do not convey any information relative to actual vehicle deceleration including, for example, more aggressive decelerations as can be invoked by downshifting, throttle pedal releases coupled with performance-type automatic transmission calibrations, or parking/hand brake applications, none of which result in brake switch closure. Such information may be of value to other vehicle operators in evaluating what vehicle control operations and with what urgency these operations should be performed.